COVID-19: more than a respiratory virus, an optical coherence tomography study

Abstract

Purpose The purpose of this study is to investigate anatomic and morphologic features of inner and outer retinal layers in patients recovered from COVID-19 with Spectral Domain Optical Coherence Tomography (SD-OCT), whether correlate with any symptoms during disease process. Methods 32 patients recovered from COVID-19 and age- and gender-matched 36 healthy controls were included in this cross-sectional study. Ganglion cell-inner plexiform layer, macular and peripapiller retinal nerve fiber layer (RNFL), inner nuclear layer (INL), outer nuclear layer (ONL), outer plexiform layer (OPL) and the outer retinal hyperreflective bands including external limiting membrane (ELM), ellipsoid zone (EZ) and interdigitation zone (IZ) were examined with SD-OCT. The differences of each retinal layers thickness among subgroup analysis of ocular pain and headache were also compared. Results Macular RNFL of inner and outer nasal and outer inferior quadrants were thinner in COVID-19 patients compared to healthy control group ( p = 0.046, p = 0.014 and p = 0.016, respectively). Thinning in outer superior quadrant of GCIPL and INL quadrants were detected in patients with headache ( p = 0.026 and p = 0.01). Superonasal and inferotemporal sectors of pRNFL were thinner in patients with ocular pain compared to patients without ocular pain ( p = 0.024 and p = 0.015). Integrity of EZ, ELM and IZ was evaluated as continuous line and protected on each OCT scans. Conclusion The study demonstrated convincing evidence that SARS-CoV-2 can affect the inner and outer retinal layers, with subclinical localized alterations, particularly in patients with headache and ocular pain symptoms during COVID-19 period. Supplementary Information The online version contains supplementary material available at 10.1007/s10792-021-01952-5.

Assessment of early and long-COVID related retinal neurodegeneration with optical coherence tomography

“…Alterations in retinal layers of patients recovered from COVID-19 were demonstrated with this study, providing that COVID-19 infection had both temporary and persistant effects in retina in early and long-term periods. At the beginning of the pandemic, thinking to be only a respiratory system virus, making an acute infection, the agent is named as Severe Acute Respiratory Syndrome Coronavirus, letter R represents respiratory, but it is shown that it is more than a respiratory virus [ 4 – 6 ], and letter A represents Acute, nevertheless it seems to be a chronic infection. As COVID-19 pandemic continues and the infected population grows, reports of persistent and prolonged effects after COVID-19 are increasing, those are need to be identified and classified [ 12 – 14 ].…”

“…Although the lungs are the main target organ, it has potential to infect other organs and ocular tissues as well [ 4 – 6 ]. The virus gains entry to host cell by binding to angiotensin converting enzyme-2 (ACE-2), which is widely expressed in human cells [ 1 , 7 ] and can cause endothelial dysfunction associated with apoptosis, either by direct viral infection of the endothelium or by immune-mediated response [ 8 ].…”

“…In our previous cross-sectional case–control research study [ 6 ], we found thinning of the inner and outer retinal layers of recovered COVID-19 patients with Spectral Domain Optical Coherence Tomography (SD-OCT) that is a non-invasive imaging technique, useful for demonstrating subclinical retinal changes in systemic conditions and viral infections as well [ 19 , 20 ]. The aim of this study is to investigate whether the OCT findings are reversible or persisting and supporting post-COVID syndrome in order to perform a follow-up protocol.…”

Optic Nerve and Retinal Layer Measurements With Optical Coherence Tomography in PCR Positive and Negative Covid-19 Patients

“…[16,17] One research found macular RNFL thickness in patients recovering from COVID-19 compared to healthy subjects. [18] Another study also showed localized thinning of RNFL in patients with COVID-19. [19] In contrast, our study could not observe a different outcome in COVID-19 patients regarding RNFL.…”

Eyeing up the pandemic: A literature review of the ocular manifestations of COVID-19

“…A retrospective cohort study compared the thickness of retinal layers in recovered COVID-19 patients with non-infected individuals; it found that 19 out of 32 recovered patients demonstrated a thinner retinal nerve-fiber layer compared to 36 of the control group. The visual implications of this finding were inconclusive but the thinning was more pronounced amongst patients complaining of associated ocular pain rather than being asymptomatic [6].…”